Unlock Japanese version of "Ring a Bell"
Finish the game once on any difficulty to have the opening song alternate between Japanese and English tracks.

New Game+
Beat the game, save your position and then start a new game. The following secrets will be available:

EX New Game
Grade Shop
Nam Cobanda Isle
Unknown Difficulty

Glitch: Repede's Body Armor
Near the end of the game, there's a chance to synthesis an armor called "Aer Fragment", at the same time, there should be 2 synthesizable armors for Yuri and Karol called "Mumbane" and "Mumbane Aer". Well, "Mumbane Aer" is an armor slightly better than "Mumbane" which needed 1 "Aer Fragment" (Repede's armor) and 1 "Mumbane" itself to synthesis it. Here comes the glitch, synthesis 1 "Aer Fragment", have Repede wearing it, then synthesis a "Mumbane" into the inventory. Now go to synthesis a "Mumbane Aer", a pop-up message will show up to tell that armor that Repede's wearing will be turn into raw material, just proceed, guess what? Repede just got an new armor which can only (suppose) wear by Yuri and Karol.